An insulated gate bipolar transistor has advantages of a low on-state voltage drop, a great current capacity, a high input impedance, a fast response speed and simple control. Therefore, the insulated gate bipolar transistor is widely applied to the fields of industry, information, new energy, medical science, transportation and so on.
Reference is made to FIG. 1, which is a schematic structural diagram of a trench gate type IGBT chip according to the conventional technology. A cell of an existing trench gate type IGBT chip includes two primary trench gates 1. A source region 2 and an emitter metal electrode 3 are arranged oppositely between the two primary trench gates, and the emitter metal electrode 3 extends to a P-base region. The existing trench gate type IGBT chip has a low turn-off speed, and thus the performance of the IGBT chip is affected.